There is ongoing interest in increasing the use of unlicensed spectrum. There is interest in aggregating unlicensed spectrum to licensed spectrum, in order to increase resources of a network when needed. Licensed assisted access (LAA) allows access to unlicensed spectrum, with assistance from a licensed network. LAA aims to port the Mobile Broadband (MBB) air interface to the unlicensed spectrum through aggregating unlicensed component carriers (CCs) at the operator's small cells. Although 5 GHz and 2.4 GHz are the current spectra of interest, LAA methods may be extendible to any other spectra.
A consideration in LAA is how to maintain efficient and fair coexistence with WLAN. Small cells (also referred to as low power nodes (LPNs)) are low-powered radio access nodes that may operate in both the licensed and unlicensed spectrum, and have a relatively short range (e.g., about 10 m to about 200 m), and can take advantage of LAA. A problem is that there may be a high density of small cell deployment for LAA as well as a high density of WLAN points, so interference may be expected to be significant. Further, WLAN typically is configured to opportunistically use more channels (e.g., per IEEE 802.11ac).